Footage has emerged showing government MP Natasha Griggs confronting a union member in the street demanding she stop filming her and knocking the phone to the ground.
In an incident that's been labelled "aggressive", Ms Griggs walks up to the filmer repeating "don't video me" before the screen goes black for a few seconds while the phone is on the ground.
The video was first shown by ABC News.
Maritime Union of Australia's Northern Territory branch secretary Thomas Mayor witnessed the incident at the NT's Palmerston Night Markets while handing out flyers about seafarers jobs.
He says Ms Griggs hit the phone out of the union member's hand.
"She's lying when she reckons the woman dropped it," he told AAP on Saturday.
"It was aggressive."
Unionists can be heard yelling "shame" after the incident.
Labor is hopeful it can reclaim Ms Griggs' marginally held seat of Solomon in the Northern Territory.
The Country Liberal Party MP won the electorate from Labor in 2010 and retained it by 1.4 per cent last election.
AAP contacted Ms Griggs' office for comment and was told she was unavailable for interview.